JPH08207263A - Method and device for ink jet printing - Google Patents

Abstract

PURPOSE: To provide the method and device for ink jet printing, which are capable of retaining an interval between the printing surface of a printing object, having different thicknesses, and an ink jet heat so as to be a predetermined interval. CONSTITUTION: A gap regulating sensor 51 is abutted against a printing surface 41 by moving relatively a motor 22, moving a transfer belt 32 and a top beam 38 relatively into the opposing directions thereof, an original point position detecting sensor 25, setting the top beam 38 and the transfer belt 32 so as to have a predetermined interval, a gap regulating sensor 51, provided at the side of the top beam 38 and capable of being abutted against the printing surface 41 of a printing object 33, the top beam 38 and the transfer belt 32, set in a predetermined interval. A device for ink jet printing is provided with a control means, driving a motor 22 reversely at this time to move the top beam 38 and the transfer belt 32 reversely to move relatively by a predetermined amount, a pulley shaft driving motor 34, moving the transfer belt 32 and the top beam 38 relatively into a direction parallel to the printing surface 41, and a main scanning screw shaft driving motor 46.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printing method and an ink jet printing apparatus capable of always maintaining a proper gap between a print surface and an ink jet head for various print objects having different thicknesses.

[0002]

2. Description of the Related Art In an ink jet system, ink droplets are ejected from an ink ejection port formed in an ink jet head toward a print surface of an object to be printed so that desired information is printed on the print surface of the object to be printed. There is. For this reason, it is important to maintain a constant distance between the ink ejection port of the inkjet head and the print surface of the print target in order to secure print quality.

Conventionally, a sheet-like paper having a thickness of about 0.15 to 0.2 mm has been considered as a print target, so that the distance between the ink ejection port of the ink jet head and the print surface of the print target is reduced. It was possible to print on paper of ordinary thickness with almost no problems, simply by making mechanical settings beforehand.

Further, a printing apparatus or the like provided with a mechanism for adjusting the distance between the ink jet head and the printing object has been put into practical use for convenience according to the type of the printing object. At most, it corresponds only to the thickness that is usually recognized as paper, such as thick paper. That is, there is no known inkjet printing apparatus that can appropriately adjust the distance between the inkjet head and the print surface of the print target for various print targets such as wood, resin, or metal.

[0005]

In recent years, by utilizing the characteristics of the ink jet system, in addition to wood, resin or metal plates, desired image information can be printed on cloth or the like, or metal plates for printing plates, etc. It is considered that the work of applying the etching liquid to the substrate is performed by an inkjet method.

In consideration of performing inkjet printing on such various print objects, it is necessary to install a mechanism capable of adjusting the distance between the ink ejection port of the inkjet head and the print surface of the print object. is there. From such a viewpoint, JP-A 1-219
As is well known in Japanese Patent Laid-Open No. 520, an inkjet printing apparatus has been proposed which incorporates a mechanism for adjusting a distance between an ink ejection port of an inkjet head and a print surface of a print target.

However, in the ink jet printing apparatus disclosed in Japanese Unexamined Patent Publication No. 1-219520, since the gap adjusting sensor is always in contact with the print surface of the print target, the print surface of the print object is streaked. There is a risk of scratches or stains on the print surface in some cases.

Further, in this conventional ink jet printing apparatus, the print target can print only a fixed thickness, and for example, the print target having a wedge-shaped change in thickness has some kind of treatment. It was not possible to print on the printed surface unless tools were used.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet printing method and an ink jet printing apparatus capable of holding an ink jet head of an ink jet unit and a print surface of a print object at predetermined intervals with respect to print surfaces of print objects having different thicknesses. To provide.

[0010]

According to a first aspect of the present invention, there is provided a print object placing portion on which a print object is placed, and an ink jet unit attaching portion to which an ink jet head facing the print object is attached. Moving means for relatively moving the mounting portion of the ink jet unit and the printing object placement portion in the facing direction, and a moving means provided on the mounting portion side of the ink jet unit for contacting the printing surface of the printing object. An ink jet printing method for printing predetermined information on a print surface of an object to be printed by using an ink jet printing apparatus having a gap adjustment sensor which can be in contact, wherein the gap adjustment sensor touches the print surface of the object to be printed. Drive the moving means in a direction in which The step of bringing the gap adjustment sensor into contact with the print surface of the print target object, and driving the moving means in reverse at the time of bringing the gap adjustment sensor into contact with the print surface of the print object. A step of relatively moving a mounting portion of the inkjet unit and the print object mounting portion by a predetermined amount in a direction in which the gap adjusting sensor is separated from the print surface of the object; and the gap from the print surface of the print object. The print surface of the print object by relatively moving the print object placement portion and the attachment portion of the inkjet unit in a direction parallel to the print surface of the print object in a state where the adjustment sensor is separated by a predetermined amount. And a step of printing predetermined information on the inkjet printing method. That.

Here, the moving means may move the print object placing portion relatively in parallel in a direction facing the attachment portion of the ink jet unit, or the print object placing portion may be moved in the width direction. It is useful to be able to tilt along a direction.

The gap adjusting sensor has a lever whose one end projects toward the print surface of the print target, and a biasing means for biasing one end of the lever toward the print surface of the print target. And a switch for detecting a displacement of the other end of the lever above a predetermined value against the biasing means. And
It is possible to move along the width direction of the print object placement portion, or two units can be provided so as to be respectively movable along the width direction of the print object placement portion.

Further, the method further comprises the step of driving the moving means to set the mounting portion of the ink jet unit and the print object mounting portion at a predetermined distance, whereby the mounting portion of the ink jet unit and the print are set. The moving means may be driven in a direction in which the gap adjustment sensor may come into contact with the print surface of the print target from a state in which the predetermined distance is set between the target placement part and the target placement part.

On the other hand, according to a second aspect of the present invention, a print object placing portion on which a print object is placed and a print object placing portion are provided so as to be relatively movable in a facing direction of the print object placing portion, and An attachment unit of an inkjet unit to which an inkjet head that can face a print surface of an object is attached; a moving unit that relatively moves the attachment unit of the inkjet unit and the print object placement unit in these opposing directions; A gap adjustment sensor that is provided on the mounting portion side of the inkjet unit and that can come into contact with the print surface of the print object, and the moving means in a direction that the gap adjustment sensor can come into contact with the print surface of the print object. When driving, when the gap adjustment sensor comes into contact with the print surface of the print target Control means for driving the moving means in the opposite direction to relatively move the attachment portion of the inkjet unit and the print object mounting portion by a predetermined amount in a direction in which the gap adjustment sensor is separated from the print surface of the print object. An inkjet printing apparatus comprising: a scanning unit configured to relatively move the print target placement unit and an attachment unit of the inkjet unit in a direction parallel to the print surface of the print target.

Here, the moving means can move the print object placing portion relatively in parallel in a direction opposite to the mounting portion of the ink jet unit, or the print object placing portion can be moved in its width. It is useful to be able to tilt along a direction.

The gap adjusting sensor has a lever whose one end projects toward the print surface of the print target, and a biasing unit which biases one end of the lever toward the print surface of the print target. And a switch that detects a displacement of the other end side of the lever above a predetermined value against the biasing means. Further, it is possible to move along the width direction of the print object placement section, or two units can be provided so as to be respectively movable along the width direction of the print object placement section.

Further, it further comprises initial setting means for setting a predetermined interval between the mounting portion of the ink jet unit and the printing object placing portion, and the control means mounts the ink jet unit by this initial setting means. The moving means may be driven in a direction in which the gap adjusting sensor may come into contact with the print surface of the print target from a state in which a portion and the print target placement part are set at a predetermined gap. . In this case, it is preferable that the initial setting unit is an origin position detection sensor for holding the mechanical position of the moving unit at a predetermined position.

It is effective that the ink jet head uses thermal energy to generate bubbles in the ink and ejects the ink based on the bubbles.

[0019]

According to the present invention, the control means drives the moving means in a direction in which the gap adjusting sensor can come into contact with the print surface of the print object to relatively move the mounting portion of the ink jet unit and the print object mounting portion. . Then, when the gap adjusting sensor comes into contact with the print surface of the print target, the moving means is driven in reverse, and the mounting portion of the inkjet unit and the print target are placed in the direction in which the gap adjusting sensor moves away from the print surface of the print target. The placing portion is moved by a predetermined amount.

As a result, the ink jet unit and the print surface of the print object are set at a predetermined distance and the gap adjusting sensor is held in a non-contact state with the print surface of the print object. The print object placement section and the attachment unit of the inkjet unit are relatively moved in a direction parallel to the print surface of the print object, and predetermined information is printed on the print surface of the print object.

Here, in the case of the print object in which the surface contacting the print object placing portion and the print surface are parallel, the moving means relatively moves the print object placing portion in the opposing direction to the mounting portion of the ink jet unit. By adopting an object that can be moved in parallel, the relative moving surface between the print surface of the print target and the mounting portion of the inkjet unit during printing becomes parallel. Further, in the case of a print object in which the surface contacting the print object placing portion and the print surface are inclined along the width direction of the print object placing portion, the print object placing portion is moved in the width direction. By adopting the one that can be inclined along the plane, the relative moving surface between the print surface of the print target and the mounting portion of the inkjet unit during printing becomes parallel.

Further, a lever having one end protruding toward the print surface side of the print object, a biasing means for biasing one end side of the lever toward the print surface side of the print object, and a resistance means against the biasing means. When using a gap adjustment sensor having a switch that detects a predetermined displacement or more on the other end side of the lever,
By driving the moving means in a direction in which the gap adjusting sensor can come into contact with the print surface of the print object, the print surface of the print object is pressed against one end side of the lever against the biasing means, and the other side of the lever is pressed. The end side begins to displace, and when it displaces more than a predetermined amount, the switch is switched and the signal is output to the control means.

When the print surface of the print object exists only in a part along the width direction of the print object mounting portion in a state of being projected from the other portions, the gap adjusting sensor is used for the print object having this print surface. It moves in the width direction of the object placing part. In addition, when the print surface of the print target is inclined along the width direction of the print target placement part, the two gap adjustment sensors are placed on both sides in the width direction of the print target to place the print target placement target. By tilting the part,
Both sides in the width direction of the print target are brought into contact with the gap adjustment sensors.

On the other hand, when the initial setting means for setting the predetermined distance between the mounting portion of the ink jet unit and the print object mounting portion is provided, the control means controls the mounting portion of the ink jet unit by the initial setting means. The moving unit is driven in a direction in which the gap adjusting sensor can come into contact with the print surface of the print target from a state in which the print target placement unit is set to a predetermined gap. When the origin position detection sensor is adopted as the initial setting means, the mechanical position of the moving means is held at a predetermined position based on the output from the origin position detection sensor, whereby the mounting portion of the inkjet unit and the print target The mounting portion is set at a predetermined interval.

When an ink jet head is used which uses thermal energy to generate bubbles in the ink and ejects the ink based on this, at least a rapid temperature rise exceeding nucleate boiling is provided corresponding to print information. By applying one drive signal to the electrothermal conversion element, heat energy is generated in the electrothermal conversion element, causing film boiling on the heat acting surface of the inkjet head, and as a result, one-to-one correspondence with this drive signal. Forming bubbles of ink. By the growth and contraction of the bubbles, ink is ejected from the ink ejection port of the inkjet head, and at least one ink droplet is formed on the print surface of the print target.

[0026]

EXAMPLES Some examples of the ink jet printing apparatus according to the present invention will be described in detail with reference to FIGS.

As shown in FIG. 1 showing a schematic structure of an embodiment in which a desired printing is performed on a rectangular plate whose printing surface is parallel to the surface on the back side and FIG. 2 showing its planar shape, Vertically upward (upper side in FIG. 1) is provided at both front and rear ends (both ends in the left-right direction in the figure) of the base plate 13 having a plurality of pedestals 12 placed on the placing surface 11 such as a floor or a table. A pair of elevating guide rods 14 are provided so as to project.

Cam shaft brackets 16 that rotatably support a pair of front and rear cam shafts 15I and 15O are provided on the front side of the base plate 13 on the left and right sides of the base plate 13 which intersect the direction of arrangement of the elevating guide rods 14, respectively. And fixed to the back side respectively. These camshaft brackets 16 are arranged so that they are parallel to each other and to the surface of the base plate 13.
A pair of front and rear cam shafts 15I, 15 rotatably supported by
Eccentric cams 17 are integrally formed on the O. Then, in order that the rotational phases of these eccentric cams 17 with respect to the cam shafts 15I, 15O always match, the endless toothed belt 19 is provided on the synchronous gears 18 provided on one end sides of the pair of front and rear cam shafts 15I, 15O, respectively. Wrapped around,
The height from the surface of the base plate 13 to the upper end surface of each eccentric cam 17 is always set to be equal.

Between the one cam shaft 15I and the cam shaft bracket 16 which supports the one cam shaft 15I,
In order to adjust the tension of the toothed belt 19, a tension adjusting mechanism (not shown) capable of moving the other cam shaft 15I relative to the cam shaft bracket 16 in the front-back direction of the base plate 13 is incorporated.

At one end of one cam shaft 15O, which is rotatably supported in a penetrating state by one cam shaft bracket 16 provided at one end of the base plate 13, the cam shaft driven gear 2 is provided.
0 and a rotary disk 21 for detecting the origin position of the cam shafts 15I and 15O, which will be described later, are provided coaxially and integrally.
The camshaft bracket 16 has a camshaft 15I,
A forward / reverse stepping motor (hereinafter, referred to as a cam shaft drive motor) 22 for driving 15O is attached, and the rotational force of a cam shaft drive gear 23 integrated with the cam shaft drive motor 22 is applied to the stepping motor 22. Camshaft driven gear 2
A reduction gear group 24 for transmitting to 0 is rotatably provided. A notch (not shown) is formed at one location on the outer peripheral edge of the rotary disc 21, and an origin position detection sensor 25 for detecting the notch is attached to the base plate 13. When the origin position detection sensor 25 detects the notch of the rotating disk 21, the distance from the cam shafts 15I and 15O to the upper end surface of the eccentric cam 17 is set to be the minimum as shown in FIG. ing.

That is, the origin position of the cam shafts 15I, 15O is the rotational phase of the cam shafts 15I, 15O at which the distance from the cam shafts 15I, 15O to the upper end surface of the eccentric cam 17 becomes the minimum, and from this state, The cam shaft drive gear 23 of the shaft drive motor 22 rotates normally, and the lifting table 2 described next
6 is raised with respect to the base plate 13. The cam shaft drive motor 22, the reduction gear group 24, the cam shaft driven gear 20, the cam shafts 15I and 15O, the eccentric cam 17 and the like constitute the moving means of the present invention.

On the other hand, the front and rear ends of the lifting table 26 mounted on the eccentric cams 17 are slidably fitted to the lifting guide rods 14 so that the back surface of the lifting table 26 slides on the eccentric cams 17. Elevating guide cylinders 27 that fit together are provided so as to project downward. Further, between the lifting table 26 and the base plate 13, the lifting table 26 is always provided with the eccentric cam 17.
A tension spring 28 for urging the elevating table 26 toward the base plate 13 side is interposed so as to come into contact with the pair of front and rear cam shafts 15 as the cam shaft drive motor 22 operates.
As I and 15O rotate synchronously, the lifting table 2
6 is on the base plate 13 along the elevating guide bar 14 in FIG.
It is designed to go up and down in the middle.

A pair of front and rear pulley shafts 29I, which are parallel to the cam shafts 15I and 15O, are provided at both front and rear ends of the lifting table 26.
Pulley shaft brackets 30 that rotatably support 29O are fixed to the left and right sides of the lifting table 26, respectively. An endless conveyor belt 32 is wound around a belt pulley 31 formed integrally with each of the pulley shafts 29I and 29O, and a print target 33 is placed at a predetermined position on the conveyor belt 32. Has become. That is, the conveyor belt 32 corresponds to the print object placing portion of the present invention.

The pulley shaft bracket 30 which supports one end of one pulley shaft 29I has a pulley shaft 29I, 2
A stepping motor (hereinafter, referred to as a pulley shaft drive motor) 34 for driving the 9O is attached, and the rotational force of a pulley shaft drive gear 35 integrated with the pulley shaft drive motor 34 is applied to one pulley shaft 29I. A reduction gear 37 for transmitting to a pulley shaft driven gear 36 provided on one end side of the is rotatably provided.

Therefore, when the pulley shaft drive motor 34 is operated, one pulley shaft 29I is driven, and accordingly, the conveyor belt 32 is rotated counterclockwise in FIG. 1, and the other end side of the lifting table 26 ( The print object 33 placed on the right side of the drawing is placed on one end side of the lifting table 26 (left side of the drawing).
It is designed to be transported to.

The tension of the conveyor belt 32 can be adjusted between the other pulley shaft 29O and the pulley shaft bracket 30 supporting the other pulley shaft 29O.
A tension adjusting mechanism (not shown) capable of moving the other pulley shaft 29O relative to the pulley shaft bracket 30 in the front-back direction of the base plate 13 is incorporated.

At the left and right ends of the top beam 38 that straddles the center of the lift table 26 in the left-right direction, the upper end of a column 40 is detachably screwed to the base plate 13 via a height adjusting block 39. Each is integrally connected. In this embodiment, in order to keep the distance between the print surface 41 of the print object 33 and the inkjet head 42 described later constant, the cam shafts 15I and 15O are driven and rotated to adjust the eccentric amount of the eccentric cam 17. However, when printing is performed on the print object 33 having a large difference in thickness that cannot be dealt with only by the eccentric amounts of the cam shafts 15I and 15O, the height adjusting block 39 having an appropriate thickness is replaced. I am able to do it. Therefore, a positioning pin 43 is provided between the base plate 13 and the column 40 so that the relative position of the column 40 with respect to the base plate 13 can always be accurately positioned.

Both ends of a unit guide rod 44 and a main scanning screw shaft 45 which are parallel to the cam shafts 15I and 15O are attached to the upper ends of the pair of left and right columns 40, and both ends of the main scanning screw shaft 45 are attached. Is rotatably supported with respect to the column 40. A forward / reverse stepping motor (hereinafter referred to as a main scanning screw shaft drive motor) 46 attached to the upper end of one column 40 is connected to one end of the main scanning screw shaft 45. The main scanning screw shaft drive motor 46 is provided in the ink jet unit 47 which is screwed with the main scanning screw shaft 45 and through which the unit guide rod 44 slidably penetrates.
With the driving of the main scanning screw shaft 45, the reciprocating motion can be performed along the unit guide bar 44 above and below the conveyor belt 32. That is, top beam 3
8, the column 40, the unit guide rod 44, the main scanning screw shaft 45, and the like correspond to the inkjet unit mounting portion of the present invention.

The ink jet unit 47 in the present embodiment is equipped with an ink jet head 42 in which a plurality of ink ejection openings (not shown) that open downward are arranged in the front and rear (in the left and right direction in the figure) at the lower end portion. ,
For example, a well-known one is used in Japanese Patent Laid-Open No. 6-199006. In this case, an ink tank (not shown) that supplies ink to the inkjet head 42 can be mounted so as to be replaceable with respect to the inkjet unit 47, or can be replaceably attached to the top beam 38 or the column 40. When the ink tank is mounted on the inkjet unit 47, it may be formed so as to be separable from the inkjet head 42 or integrally formed with the inkjet head 42.

As shown in FIG. 2 and FIG. 3 in which the upper end of the column 40 is extracted and enlarged, the guide rod support arm 48 protruding from the upper end of the column 40 to the other end of the lifting table 26 has a cam shaft. Both ends of a sensor holder guide bar 49 parallel to 15I and 15O are connected to each other. The sensor holder guide bar 49 has a medium front end detection sensor 50 for detecting loading of a print target 33, an inkjet head 42 and a print target. A sensor holder 52, in which a gap adjusting sensor 51 for properly adjusting the gap with the object 33 is attached to the front and rear, slidably penetrates. At the upper end of the sensor holder 52, the tip is the sensor holder guide rod 4
A set screw 53 that abuts 9 is screwed in. By screwing the set screw 53 into the sensor holder 52, the relative position of the sensor holder 52 along the longitudinal direction of the sensor holder guide rod 49 can be arbitrarily fixed. It is like this. Immediately below the sensor holder guide bar 49, a detent bar 55 slidably engaged with a detent groove 54 formed at the lower end of the sensor holder 52 is arranged in parallel with the sensor holder guide bar 49. Both ends of the detent bar 55 are also integrally connected to the guide bar support arm 48.

In this embodiment, since the position of the sensor holder 52 can be moved along the sensor holder guide rod 49, as shown in FIGS. 4 and 5 showing the appearance of the print object 33. In addition, the print surface 41 to be printed with respect to the print target 33 protrudes from other portions, and the print surface 41 to be printed is present only in a part thereof along the width direction of the print target 33. Even in such a case, the sensor holder 52 should be attached to the printed surface 4
By moving the print object 33 directly above 1, it is possible to print on the print surface 41 of the print target object 33 as shown in FIGS. 4 and 5 without any problem.

Medium leading edge detection sensor 50 in this embodiment
Uses a reflection type photoelectric switch, and detects the tip position of the print target 33 carried into the inkjet unit 47 side in a non-contact state. Further, the gap adjusting sensor 51 in the present embodiment includes a swing lever 56 having a bell crank shape, and a pivot pin 57 that pivotally attaches a central portion of the swing lever 56 to the sensor holder 52.
And a pulling member provided between the upper end of the swing lever 56 and the sensor holder 52 so that the lower end of the swing lever 56 faces downward, that is, biases counterclockwise about the pivot pin 57 in FIG. It comprises a spring 58 and a sensor switch 59 such as a transmissive photoelectric switch. And the tension spring 58
When the upper end of the swing lever 56 is rotated clockwise by a predetermined amount or more against the spring force of, and the upper end of the swing lever 56 overlapping the sensor switch 59 is separated from the sensor switch 59 by a predetermined amount, The signal output from the gap adjusting sensor 51 is set to be turned on.

In this way, the printing target 33 is mechanically printed.
Since the lower end of the swing lever 56 is brought into contact with the print surface 41 of No. 3, it is possible to always accurately set the distance between the print surface 41 of the print target 33 and the inkjet head 42. Further, in this embodiment, when the gap adjusting sensor 51 is turned on, the normal rotation of the cam shaft drive motor 22 is stopped, and when the cam shaft drive motor 22 is further rotated in the predetermined amount, the print target 33 is printed.
The gap G (see FIG. 3) between the print surface 41 of the print head 41 and the inkjet head 42 is set to be an appropriate distance, whereby the gap adjusting sensor 51 is temporarily attached to the print surface 41 of the print target 33. I try to stop it just by making a physical contact.

In order to realize the above-described operation, as shown in FIG. 6 showing the control block of this embodiment, the ink jet unit 47 operates the pulley shaft drive motor 34, the main scanning screw shaft drive motor 46, and the like. A print control circuit 60 for controlling the printer is mounted. Further, on the back side of the base plate 13, a power supply unit 62 accommodating a power supply circuit 61 for supplying stable power to the motors 22, 34, 46, and a camshaft drive motor in a preset operation sequence. Gap adjusting circuit 63 for driving 22
And an interface board 65 for transmitting print information input to the personal computer 64 to the print control circuit 60 of the inkjet unit 47. The detection signals from the sensors 25 and 51 are passed through the sensor detection circuit 66 and the gap adjustment circuit 6
3 is output.

On the upper surface of the top beam 38, a plurality of types of print switches 67 operated by an operator, a gap adjustment start switch 68, etc. are attached. The print switch 67 is connected to the print control circuit 60 together with the medium leading edge detection sensor 50 described above, and the gap adjustment start switch 68 is connected to the gap adjustment circuit 63.

As shown in FIG. 7 showing the operation procedure of the present embodiment, when the operator presses the gap adjustment start switch 68 in step S1, it is determined in step S2 whether or not the origin position detection sensor 25 is turned on. judge. If it is determined that the origin position detection sensor 25 is not turned on, S3
In step S4, the cam shaft drive motor 22 is rotated in the reverse direction, and in step S4, it is determined again whether or not the origin position detection sensor 25 is on. And the origin position detection sensor 2
If it is determined that 5 is not on, the process returns to step S3 to continue the reverse rotation operation of the cam shaft drive motor 22.

In this way, when it is determined in step S4 that the origin position detection sensor 25 is turned on,
The reverse rotation operation of the cam shaft drive motor 22 is stopped in step S5, and the normal rotation operation of the cam shaft drive motor 22 is started in step S6. When it is determined that the origin position detection sensor 25 is turned on in step S2, the process directly proceeds to step S6 and the forward rotation operation of the cam shaft drive motor 22 is started. Then, in step S7, it is determined whether the gap adjustment sensor 51 is on,
If it is determined that this is not turned on, the process returns to step S6 to continue the normal rotation operation of the cam shaft drive motor 22.

In this way, when it is determined in step S7 that the gap adjusting sensor 51 is turned on, S
In step S8, the normal rotation operation of the cam shaft drive motor 22 is stopped, and in step S9, the cam shaft drive motor 22 is reversely rotated by a predetermined amount. Then, in step S10, the cam shaft drive motor 22 is rotated. The operation of the ink jet head 42 and the print surface 4 of the print object 33 are stopped.
The gap adjustment with 1 is completed.

Thereafter, the operator presses the print switch 67 to operate the pulley shaft drive motor 34, and when the medium front end detection sensor 50 confirms the front end of the print target 33, the print control circuit 60 causes the pulley shaft drive motor 34 to move. 34 and the main scanning screw shaft drive motor 46 are controlled to print predetermined image information at a predetermined position on the print surface 41 of the print target 33, and the print target 33 after printing is moved to one end side of the lifting table 26. To carry out.

When the thickness of the print object 33 is gradually increased along the scanning direction of the conveyor belt 32 by the pulley shaft drive motor 34, the gap adjusting sensor 51 may be turned on during the printing operation. is there. In such a case, there is a possibility that good quality printing may not be possible. Therefore, in this embodiment, the gap adjusting sensor 5 is used during the printing operation.
When 1 is turned on, the operation of the pulley shaft drive motor 34 is stopped to prevent the gap adjusting sensor 51 from being damaged and the printing operation is interrupted.

The above-described embodiment can be applied to the case where the back surface of the print object 33 which is in contact with the conveyor belt 32 and the print surface 41 are parallel to each other, but the width direction orthogonal to the conveyor direction of the conveyor belt 32. The present invention can be applied to the print target object 33 whose thickness gradually changes along the line.

FIG. 8 shows a plane structure of another embodiment of the present invention, and FIG. 9 shows a sectional structure taken along the line IX-IX. The members basically have the same functions as those of the previous embodiment. Are denoted by the same reference numerals, and description thereof will be omitted.
That is, at the front and rear ends of the back surface of the lifting table 26,
A fork-shaped connecting portion 70 formed at the upper end of the elevating guide rod 14 is pivotally pivoted via a connecting pin 69 extending in a direction parallel to the conveyance direction (left and right direction in the drawing) of a print target (not shown). The front and rear connecting pins 69 are attached to each other in a straight line. In addition, lifting guide cylinders 27a, 27 that slidably hold these lifting guide bars 14
b are attached to both the front and back sides of the front and rear ends of the base plate 13, and in this embodiment, the elevating guide bar 14 is the base plate 1.
3 can be penetrated. These lifting guide tubes 2
A pair of left and right cam shafts 15L and 15R facing each other with the front and rear elevating guide cylinders 27 sandwiched therebetween are rotatably supported on the left and right sides of the base plate 13 which intersects the front and rear arrangement direction of 7, respectively. Brackets 16 are fixed to the front side and the rear side of the base plate 13, respectively. Eccentric cams 17L and 17R are integrally formed on the pair of left and right cam shafts 15L and 15R that are rotatably supported by the cam shaft brackets 16 so as to be parallel to each other and parallel to the surface of the base plate 13. Has been done.

On one end side of the cam shafts 15L and 15R, which are rotatably supported in a penetrating state on the left and right cam shaft brackets 16 located on one end side of the base plate 13, the cam shaft driven gear 2 is provided.
0 and a rotating disk 21 for detecting respective origin positions of the cam shafts 15L and 15R, which will be described later, are provided coaxially and integrally. Further, cam shaft drive motors 22L and 22R capable of forward and reverse rotation for independently driving the cam shafts 15L and 15R are attached to the cam shaft brackets 16, and the cam shaft drive motors 22L and 2R are further installed.
A reduction gear group 24 for transmitting the rotational force of the camshaft drive gear 23 integral with the 2R to the camshaft driven gear 20 is rotatably provided. Notches (not shown) are formed on the outer peripheral edge of the rotary disc 21 at one location, and origin position detection sensors 25L, 25R for detecting these notches are attached to the base plate 13, respectively. Then, these origin position detection sensors 25
When L and 25R detect the notch of the rotary disk 21, the distance from the cam shafts 15L and 15R to the upper end surfaces of the eccentric cams 17L and 17R is set to be the minimum.

That is, the origin positions of the cam shafts 15L, 15R are from the cam shafts 15L, 15R to the eccentric cams 17L, 1R.
Camshaft 15L, 1 which minimizes the distance to the top surface of 7R
The rotational phase is 5R, and from this state, the camshaft drive gears 23 of the camshaft drive motors 22L and 22R rotate in the normal direction to raise the lifting table 26 with respect to the base plate 13.

A sensor holder guide bar 49, both ends of which are connected to a support arm 48 of the column 40, has a medium front end detection sensor 50 for detecting the carry-in of a print object and the left side of the elevating table 26 (lower side in FIG. 8). ), A sensor holder 52 having a gap adjustment sensor 51L attached to the front and rear for appropriately adjusting the gap between the print object and the inkjet head 42, and the right side of the lifting table 26 (see FIG. 8).
The sub-sensor holder 71, to which a gap adjusting sensor 51R for appropriately adjusting the gap between the print object and the inkjet head 42 located on the upper side) is slidably penetrated. These sensor holders 52
A set screw 53 whose tip abuts the sensor holder guide rod 49 is screwed into the upper end portion of the sub sensor holder 71, and the set screw 53 is attached to the sensor holder 5.
By screwing into the sensor holder guide rod 49, the relative position of the sensor holder 52 along the longitudinal direction of the sensor holder guide rod 49 can be arbitrarily fixed. The position of the sensor holder 71 is moved according to the width of the print target.

In this embodiment, the gap adjusting sensor 51L,
The forward rotation of the camshaft drive motors 22L and 22R respectively stops when the 51R is turned on, and when the camshaft drive motors 22L and 22R are respectively reversed by a predetermined amount, the print surface of the print target and the inkjet head The distance to 42 is set to be an appropriate distance. That is, when the thickness of the print target in the width direction intersecting the transport direction of the print target changes in a wedge shape, the one of the gap adjusting sensors 51L, 51R that is located on the thicker side is the first. The one that is turned on at the same time as the one located on the thinner side is turned on after that, and the connecting pin 6
Lifting table 2 located on the thin side with 9 as the center
The 6 side rises higher and is inclined, and the print surface of the print target is held parallel to the unit guide rod 44 and the main scanning screw shaft 45.

In the two embodiments described above, the base plate 13
The height of the inkjet unit 47 from the above is fixed, and the elevation table 26 on which the print target 33 is placed is moved up and down to adjust the gap between the print target 33 and the inkjet head 42. The height from the upper end surface of the conveyor belt 32 to the base plate 13 is fixed to the inkjet unit 47.
It is also possible to adjust the gap between the print target 33 and the inkjet head 42 by moving up and down.

FIG. 10 shows a plane structure of another embodiment of the present invention. Members having basically the same functions as those of the previous embodiment are designated by the same reference numerals, and the description thereof will be omitted. I shall. That is, a pair of front and rear pulley shafts 29 is provided at both front and rear end portions (both end portions in the left-right direction in the drawing) of the base plate 13.
Pulley shaft brackets 30 that rotatably support I and 29O are fixed to the left and right sides of the base plate 13, respectively. An endless conveyor belt 32 is wound around a belt pulley 31 formed integrally with each of the pulley shafts 29I and 29O, and a print target 33 is placed at a predetermined position on the conveyor belt 32. Has become. A pulley shaft driving motor 34 for driving the pulley shafts 29I and 29O is attached to a pulley shaft bracket 30 that supports one end of one pulley shaft 29I. Further, a pulley shaft driving motor 34 that is integral with the pulley shaft driving motor 34 is driven. A reduction gear 37 is rotatably provided for transmitting the rotational force of the gear 35 to a pulley shaft driven gear 36 provided at one end of one pulley shaft 29I.

On the back surface of the lower end of the column 40 extending downward from the left and right ends of the top beam 38 straddling the conveyor belt 32,
Elevating guide cylinders 27 slidably fitted to a pair of vertically elevating guide bars 14 protruding vertically upward from both left and right ends of the base plate 13 are provided so as to protrude downward, whereby the column 40 and the top beam 38 are provided. It is movable up and down with respect to the base plate 13.

A pair of left and right cam shafts 15 orthogonal to the pulley shafts 29I and 29O are provided on both left and right sides of the base plate 13.
Cam shaft brackets 16 that rotatably support L and 15R are fixed to the front and rear sides of the base plate 13, respectively. Eccentric cams 17 are integrally formed on the pair of left and right cam shafts 15L and 15R that are rotatably supported by the cam shaft brackets 16 so as to be parallel to each other and parallel to the surface of the base plate 13. There is.
The synchronous gear 1 provided on one end side of each of the pair of left and right cam shafts 15L and 15R so that the rotational phases of these eccentric cams 17 with respect to the cam shafts 15L and 15R always match.
An endless toothed belt 19 is wound around 8, and the height from the surface of the base plate 13 to the upper end surface of each eccentric cam 17 is always set to be equal.

On one end side of one cam shaft 15L rotatably supported in a penetrating state on one cam shaft bracket 16 provided at one end side of the base plate 13, the cam shaft driven gear 2 is provided.
0 and a rotary disk 21 for detecting the origin position of the cam shafts 15L and 15R, which will be described later, are provided coaxially and integrally.
The camshaft bracket 16 includes a camshaft 15L,
A cam shaft drive motor 22 capable of rotating in the forward and reverse directions for driving 15R is mounted, and the rotational force of a cam shaft drive gear 23 integrated with the cam shaft drive motor 22 is applied to the cam shaft driven gear 2
A reduction gear group 24 for transmitting to 0 is rotatably provided. Further, an origin position detection sensor 25 for detecting a notch formed on the outer peripheral edge of the rotary disc 21 is attached to the base plate 13. Then, when the origin position detection sensor 25 detects the notch of the rotating disk 21, the distance from the cam shafts 15L, 15R to the upper end surface of the eccentric cam 17 is set to be the minimum.

The lower end surfaces of the left and right columns 40 are mounted on the left and right eccentric cams 17, respectively, and are held in a state in which they are always in contact with each other by a tension spring (not shown). Then, similarly to the embodiment shown in FIGS. 1 to 7, the normal rotation of the cam shaft drive motor 22 from the origin position is started and the eccentric cam 17 is synchronously rotated, whereby the top beam 3 is rotated.
It is possible to adjust the distance between the inkjet head 42 of the inkjet unit 47 attached to the No. 8 and the print surface 41 of the print target 33 on the conveyor belt 32 to an appropriate distance in a non-contact state.

In the above-described embodiment, the number of parts can be reduced as compared with the previous embodiment because the lifting table 26 is unnecessary, and when the weight of the print target 33 and its transporting device is large, it is smaller. A driving force motor can be used. Further, the invention can be applied to the case where the back surface of the print object 33 that is in contact with the conveyor belt 32 and the print surface 43 are parallel to each other. However, as in the embodiment shown in FIGS. Naturally, it is possible to correspond to the print target object 35 whose thickness gradually changes along the width direction orthogonal to the.

FIG. 11 shows a plane structure of such another embodiment of the present invention, and FIG. 12 shows a sectional structure taken along line XII-XII of FIG.
However, since this embodiment is a combination of the embodiment shown in FIG. 8 and the embodiment shown in FIG. 10, the members having basically the same functions as those of the previous embodiment are the same as those of the previous embodiment. The reference numerals are given and the description thereof is omitted. That is, in this embodiment, the camshaft drive motors 22L and 22R are activated when the clearance adjusting sensors 51L and 51R are turned on.
Is stopped, and when the cam shaft drive motors 22L and 22R are respectively rotated by a predetermined amount, the distance between the print surface 41 of the print object 33 and the inkjet head 42 is set to an appropriate distance. ing. That is, when the thickness of the print object 33 in the width direction intersecting the conveyance direction of the print object 33 changes in a wedge shape, one of the gap adjusting sensors 51L and 51R that is located on the thicker side. Is turned on first and the one located on the thinner side is turned on thereafter, and the side of the base plate 13 located on the thinner side rises higher and becomes inclined, so that the printing surface of the printing object is a unit. It is held parallel to the guide rod 44 and the main scanning screw axis 45.

Therefore, the upper end of the elevating guide bar 14 is rotatably connected to the lower end of the column 40 via the connecting pin 69, and the lower part of the elevating guide bar 14 is attached to both front and back surfaces of the base plate 13. The lift guide cylinders 27a and 27b are slidably fitted. The connecting pin 69 can move along the arcuate elongated hole 72 formed in the column 40. Further, the column 40 and the top beam 38 are detachably connected via a height adjusting block (not shown) so as to cope with the case where the thickness of the print object 33 exceeds the eccentric amount of the eccentric cams 17L, 17R. It is preferable.

In the above-described embodiment, the print target 33 is transported by the transport belt 32, but the weight of the print target 33 holds the ink jet unit 47 and drives the top beam 38 and the column 40.
When the weight of the portion including the above is large, the top beam 38 and the column 40 on which the inkjet unit 47 is mounted may be conveyed to the base plate 13 so that a motor having a smaller driving force can be used.

FIG. 13 shows the appearance of such another embodiment of the present invention. Members having basically the same functions as those of the previous embodiment are designated by the same reference numerals, and the description thereof will be omitted. And That is, the column guide rods 73 and the sub-scanning screw shafts 74 are arranged parallel to each other on the left and right sides of the base plate 13 along the longitudinal direction thereof, and both ends of these are arranged on the base plate 1.
A pair of bracket portions 75I formed at both front and rear ends of 3,
It is held at 75O. In addition, these column guide rods 7
3, an eccentric cam 17 is integrally formed on a pair of left and right cam shafts 15L and 15R, both ends of which are rotatably attached to a pair of front and rear bracket portions 75I and 75O in parallel with 3 and the sub-scanning screw shaft 74. There is. The left and right ends of the eccentric cam 17 are placed on the front and rear ends of the lifting table 26.
An elevating guide cylinder 27 slidably fitted to an elevating guide rod (not shown) that is vertically projectingly provided on the base plate 13 is vertically projectingly projecting.

In order that the rotational phases of these eccentric cams 17 with respect to the cam shafts 15L, 15R always match, the synchronous gears 18 provided on one end sides of the pair of left and right cam shafts 15L, 15R have endless toothed belts. The height 19 from the surface of the base plate 13 to the upper end surface of each eccentric cam 17 is always set to be equal. One camshaft 1
5R has a cam shaft drive motor 22 attached to one bracket portion 75I and an origin position detection (not shown) for detecting the origin position where the distance from the cam shafts 15L and 15R to the upper end surface of the eccentric cam 17 is minimum. The sensor is connected.

The column 40L slidably fitted along the column guide rod 73 and the column 40R screwed to the sub-scanning screw shaft 74 are integrally connected via a connecting beam 76, and the other side. The sub-scanning screw shaft 74 is connected to the column drive motor 77 attached to the bracket portion 75O. The left and right ends of the unit guide rod 44 and the main scanning screw shaft 45, which are orthogonal to the column guide rod 73 and the sub scanning screw shaft 74, are attached to one end of the columns 40L and 40R, respectively. Left and right ends of a sensor holder guide rod 49 and a rotation stop rod 55, which are parallel to the unit guide rod 44 and the main scanning screw shaft 45, are attached to the end side.

As a result, the lifting table 26 is lifted and lowered by the operation of the cam shaft drive motor 22, and the lifting table 2 is moved.
Print surface 41 of print object 33 placed on 6
The gap between the inkjet unit 47 and the inkjet head (not shown) is appropriately adjusted by the gap adjusting sensor 51 mounted on the sensor holder 52. The printing operation is carried out by the vertical movement of the inkjet unit 47 by the intermittent drive of the column drive motor 77 and the width direction of the inkjet unit 47 by the drive of the main scanning screw shaft drive motor 46.

As a means for driving the columns 40L, 40R in the vertical direction, it is possible to employ a linear pulse motor having a higher speed response.

FIG. 14 shows a plane structure of such another embodiment of the present invention. Members having basically the same functions as those of the previous embodiment are designated by the same reference numerals, and the description thereof will be omitted. I shall. That is, on the left and right sides of the base plate 13, a pair of column guide bars 73L, 73R are provided along the longitudinal direction thereof.
Are arranged parallel to each other, and both ends of these are arranged on the base plate 1.
A pair of bracket portions 75I formed at both front and rear ends of 3,
It is held at 75O. In addition, these column guide rods 7
Eccentric cams 17L and 17R are integrally formed on the pair of left and right cam shafts 15L and 15R, both ends of which are rotatably attached to the pair of front and rear brackets 75I and 75O in parallel with 3L and 73R. These eccentric cams 17
Lifting table 26 with left and right ends placed on L and 17R
A connecting pin 69 as shown in FIG. 9, a connecting portion 70 of the elevating guide rod 14 (neither of which is shown), an elevating guide cylinder 27a, and the like are interposed between the front and rear ends of the base plate 13 and the base plate 13. The elevating table 26 can be tilted left and right via the connecting pin.

On one end side of the cam shafts 15L and 15R,
The cam shaft drive motors 22L and 22R attached to one of the bracket portions 75I and the cam shafts 15L and 1
An origin position detection sensor (not shown) for detecting the origin position where the distance from 5R to the upper end surface of each eccentric cam 17L, 17R is minimized is connected. Further, a linear pulse motor 79 having a stator coil 78 laid on the base plate 13 along the column guide rod 73R is interposed between the one column 40R and the base plate 13.

As a result, the elevating table 26 is tilted according to the widthwise thickness of the print object 33 placed on the elevating table 26, and the print surface 41 of the print object 33 is held parallel to the base plate 13. The print surface 41 of the print target 33 and the inkjet unit 4 are
The gap between the ink jet head 7 and an inkjet head (not shown) is equal to the gap adjusting sensor 51L mounted on the sensor holder 52 and the gap adjusting sensor 51 mounted on the sub sensor holder 71.
Adjusted appropriately by R.

In the above embodiment, the ink jet unit 47 is made to scan in the width direction of the printing object 33, but the ink ejection ports are arranged over the entire width of the top beam 38 or the connecting beam 76. did,
When a so-called full-line type inkjet head is used, a mechanism for scanning the inkjet head in the width direction of the print target 33 can be omitted. Further, in the above-described embodiment, the eccentric cams 17, 1
Lifting table 2 using 7I, 17O, 17L, 17R
Although the 6 and the column 40 are moved up and down, it is of course possible to adopt an elevating mechanism having another known structure.

In the present invention, among the ink jet systems, an ink jet head is used which prints by ejecting a liquid (hereinafter referred to as ink) drop of ink or paint by utilizing thermal energy. This is an excellent effect in an inkjet printing apparatus.

Regarding its typical structure and principle, for example, the basic principle disclosed in US Pat. No. 4,723,129 and US Pat. No. 4,740,796 is used. What is done is preferred. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or ink path holding the ink droplets. At least 1 for the electrothermal transducing element, which has a rapid temperature rise exceeding nucleate boiling corresponding to the print information.
By applying two drive signals, heat energy is generated in the electrothermal conversion element, causing film boiling on the heat-acting surface of the inkjet head, and as a result, ink bubbles that correspond one-to-one to this drive signal are formed. It is effective because it can be done. Ink is ejected from the ejection port by the growth and contraction of the bubble, and at least one ink droplet is formed. It is more preferable to make this drive signal in a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, and ink droplets with particularly excellent responsiveness can be achieved. As the pulse-shaped driving signal, those described in US Pat. No. 4,463,359 and US Pat. No. 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 relating to the rate of temperature rise of the heat acting surface are adopted, more excellent printing can be performed.

The present invention can also be effectively applied to a full-line type ink jet head having a length corresponding to the maximum width of a print target printable by the ink jet printing apparatus. This print head may be one that satisfies the width described above by combining a plurality of print heads, or may be one that satisfies the width described above by a single print head.

In addition to this, even in the case of the serial type as in the above-described embodiment, the ink jet head fixed to the apparatus main body or the apparatus main body can be electrically connected to the apparatus main body or from the apparatus main body. The present invention is also effective when a replaceable chip-type inkjet head capable of supplying the above ink or a cartridge-type inkjet head in which an ink tank is integrally provided in the inkjet head itself is used.

Further, as the constitution of the ink jet printing apparatus of the present invention, it is preferable to add the ejection recovery means of the ink jet head, preliminary auxiliary means and the like because the effects of the present invention can be further stabilized. Specific examples of these are: a capping unit for the inkjet head, a cleaning unit, a pressurizing or suction unit, an electrothermal conversion element, a heating element other than this, or a combination of these and the preliminary heating. The heating means and the preliminary discharge means for performing discharge different from the print can be mentioned.

Regarding the type and number of ink-jet heads to be mounted, for example, only one ink-jet head is provided corresponding to a single color ink, or a plurality of ink-jet heads corresponding to a plurality of inks having different color tones and densities. The number may be provided.

[0082]

According to the ink jet printing method and apparatus of the present invention, the moving means is driven in a direction in which the gap adjusting sensor can contact the print surface of the print object, and the gap is adjusted on the print surface of the print object. When the sensor abuts, the moving means is driven in reverse, and the mounting portion of the ink jet unit and the print object mounting portion are relatively moved in the direction in which the gap adjustment sensor moves away from the print surface of the print object, and printing is performed. After the gap adjustment sensor is brought into a non-contact state from the print surface of the print object, the print object mounting portion and the mounting portion of the inkjet unit are relatively moved in a direction parallel to the print surface of the print object to be printed. Since the specified information is printed on the print surface, it is possible to print on the print surface of objects with different thickness. And a printed surface of the ink jet head and the printing object ink jet unit reliably it is possible to hold a predetermined interval, it is possible to achieve good ink jet printing method and apparatus for quality Te.

Even if the print object is a wedge-shaped plate material whose thickness gradually changes along the width direction, the print object is printed such that its print surface is parallel to the scanning surface of the ink jet unit during printing operation. Since the object placing portion is inclined in the width direction, the printing operation can be performed without any problem.

Moreover, since the gap adjusting sensor and the print surface of the print object are kept in non-contact with each other during the printing operation, there is no possibility that the print surface is damaged by the gap adjusting sensor.

[Brief description of drawings]

FIG. 1 is a cutaway side view showing a schematic structure of an embodiment of an inkjet printing apparatus according to the present invention.

FIG. 2 is a plan view of the embodiment shown in FIG.

FIG. 3 is an extracted enlarged cross-sectional view of a portion of the inkjet unit in FIG.

FIG. 4 is a perspective view showing the appearance of a print target applicable to the embodiment shown in FIG.

5 is a perspective view showing the appearance of another print target applicable to the embodiment shown in FIG. 1. FIG.

FIG. 6 is a control block diagram of the embodiment shown in FIG.

FIG. 7 is a flowchart showing a procedure of a gap adjusting operation in the embodiment shown in FIG.

FIG. 8 is a plan view showing a schematic structure of another embodiment of the inkjet printing apparatus according to the present invention.

9 is a sectional view taken along the line IX-IX in FIG.

FIG. 10 is a plan view showing a schematic structure of another embodiment of the inkjet printing apparatus according to the present invention.

FIG. 11 is a plan view showing a schematic structure of another embodiment of the inkjet printing apparatus according to the present invention.

12 is a sectional view taken along the line XII-XII in FIG.

FIG. 13 is a perspective view showing an appearance of a schematic structure of still another embodiment of the inkjet printing apparatus according to the present invention.

FIG. 14 is a perspective view showing an appearance of a schematic structure of still another embodiment of the inkjet printing apparatus according to the present invention.

[Explanation of symbols]

 11 mounting surface 12 pedestal 13 base plate 14 lift guide rods 15I, 15O, 15L, 15R camshaft 16 camshaft bracket 17, 17L, 17R eccentric cam 18 synchronous gear 19 toothed belt 20 camshaft driven gear 21 rotating disk 22 , 22L, 22R cam shaft drive motor 23 cam shaft drive gear 24 reduction gear group 25, 25L, 25R origin position detection sensor 26 lift table 27, 27a, 27b lift guide tube 28 tension spring 29I, 29O pulley shaft 30 pulley shaft bracket 31 Belt pulley 32 Conveyor belt 33 Print target 34 Pulley shaft drive motor 35 Pulley shaft drive gear 36 Pulley shaft driven gear 37 Reduction gear 38 Top beam 39 Height adjustment block 40, 40L, 40R Column 41 Print surface 42 Inkjet head 43rd place Locating pin 44 Unit guide rod 45 Main scanning screw shaft 46 Main scanning screw shaft drive motor 47 Inkjet unit 48 Guide rod support arm 49 Sensor holder guide rod 50 Medium edge detection sensor 51, 51L, 51R Gap adjustment sensor 52 Sensor holder 53 Stop Screw 54 Non-rotating groove 55 Non-rotating rod 56 Swing lever 57 Pivoting pin 58 Tension spring 59 Sensor switch 60 Print control circuit 61 Power supply circuit 62 Power supply unit 63 Gap adjustment circuit 64 Personal computer 65 Interface board 66 Sensor detection circuit 67 Print Switch 68 Gap adjustment start switch 69 Connection pin 70 Connection part 71 Sub-sensor holder 72 Long hole 73 Column guide bar 74 Sub-scanning screw shaft 75I, 75O Bracket part 76 Connection beam 77 Column drive Dynamic motor 78 Stator coil 79 Linear pulse motor

Claims (16)

[Claims] 1. A print target placement part on which a print target is placed, an inkjet unit mount to which an inkjet head facing the print target is mounted, the inkjet unit mount and the print target mount. An inkjet printing apparatus is used that includes a moving unit that relatively moves the placing section in these opposing directions, and a gap adjustment sensor that is provided on the mounting section side of the inkjet unit and that can come into contact with the print surface of the print target. An inkjet printing method for printing predetermined information on a print surface of the print object, wherein the moving means is driven in a direction in which the gap adjustment sensor can come into contact with the print surface of the print object. The gap on the printed surface of the object A step of bringing the alignment sensor into contact with the print object, and the drive means is driven in reverse when the gap adjustment sensor is brought into contact with the print surface of the print object to adjust the gap from the print surface of the print object. A step of relatively moving a mounting portion of the inkjet unit and the print target placement portion in a direction in which the sensor is separated, in a state where the gap adjustment sensor is separated from the print surface of the print target by a predetermined amount, Printing the predetermined information on the print surface of the print object by relatively moving the print object placement portion and the attachment portion of the inkjet unit in a direction parallel to the print surface of the print object. An inkjet printing method characterized by comprising: 2. The moving means is capable of moving the printing object placement portion relatively in parallel in a direction facing the attachment portion of the inkjet unit. Inkjet printing method. 3. The ink jet printing method according to claim 1, wherein the moving means is capable of inclining the print object placement portion along a width direction thereof. 4. The lever, the one end of which is protruded toward the print surface side of the print object, in the gap adjustment sensor,
The lever has an urging means for urging one end side of the lever toward the print surface side of the printing object, and a switch for detecting a displacement of the other end side of the lever above a predetermined value against the urging means. The inkjet printing method according to claim 1, 2 or 3, wherein 5. The gap adjustment sensor can move along the width direction of the print object placement portion, according to claim 1, 2, 3 or 4. The inkjet printing method described in 1. 6. The two gap adjusting sensors are provided so as to be movable along the width direction of the print object placing portion, respectively.
Alternatively, the inkjet printing method according to claim 4. 7. The method further comprises the step of driving the moving means to set a predetermined interval between the mounting portion of the inkjet unit and the printing object placement portion, whereby the mounting portion of the inkjet unit and the printing are performed. The moving means is driven in a direction in which the gap adjusting sensor can come into contact with the print surface of the print target from a state in which the predetermined distance is set between the target placement part and the target placement part. Item 1 or claim 2
Alternatively, the inkjet printing method according to claim 3, claim 4, claim 5, or claim 6. 8. A print target placement section on which a print target is placed, and a print target placement section that is movable relative to the print target placement section and can face the print surface of the print target. An attachment unit of the inkjet unit to which the inkjet head is attached, a moving unit that relatively moves the attachment unit of the inkjet unit and the print target placement unit in a direction opposite to each other, and is provided on the attachment unit side of the inkjet unit. And a gap adjusting sensor that can come into contact with the print surface of the print target, and the moving unit in a direction in which the gap adjusting sensor can come into contact with the print surface of the print target. When the gap adjusting sensor comes into contact with the print surface, the moving means is driven in reverse, Control means for relatively moving the mounting portion of the ink jet unit and the printing object mounting portion by a predetermined amount in a direction in which the gap adjusting sensor is separated from the printing surface of the printing object; and the printing object mounting portion. An inkjet printing apparatus, comprising: a scanning unit that relatively moves an attachment unit of the inkjet unit in a direction parallel to the print surface of the print target. 9. The apparatus according to claim 8, wherein the moving means is capable of relatively moving the print object placing portion in parallel in a direction facing the attachment portion of the inkjet unit. Inkjet printing device. 10. The inkjet printing apparatus according to claim 8, wherein the moving unit is capable of inclining the print object placement portion along a width direction thereof. 11. The gap adjusting sensor includes a lever whose one end projects toward the print surface of the print target, and a biasing unit which biases one end of the lever toward the print surface of the print target. And a switch for detecting a displacement of the other end side of the lever that is greater than or equal to a predetermined value against the biasing means. Inkjet printing device. 12. The gap adjusting sensor is movable along the width direction of the print object placement portion.
1. The inkjet printing apparatus described in 1. 13. The two gap adjustment sensors are provided so as to be movable along the width direction of the print object placement portion, respectively. The inkjet printing apparatus described in 1. 14. The apparatus further comprises initial setting means for setting a mounting portion of the ink jet unit and the print object mounting portion at a predetermined distance, and the control means mounts the ink jet unit by the initial setting means. The moving unit is driven in a direction in which the gap adjusting sensor can come into contact with the print surface of the print target from a state in which a portion and the print target placement unit are set to a predetermined gap. The ink jet printing apparatus according to claim 8, claim 9, claim 10, claim 11, claim 12, or claim 13. 15. The ink jet printing apparatus according to claim 14, wherein the initial setting unit is an origin position detection sensor for holding the mechanical position of the moving unit at a predetermined position. 16. The ink jet head according to claim 8, wherein the ink jet head uses thermal energy to generate bubbles in the ink and ejects the ink based on the bubbles. Alternatively, the ink jet printing apparatus according to claim 11 or claim 12 or claim 13 or claim 14 or claim 15.